1. Field of the Invention
The present invention is directed to a steering wheel for use with an automobile.
2. Description of the Prior Art
A conventional steering wheel is typically composed of a boss, spoke core pieces extending outwardly from the boss in the radial outer directions, and end portions for connecting the spoke core pieces to a ring core piece, whereby the circumference of each end portions on the side of the spoke core piece is covered with a synthetic resin layer formed by an injection molding process (including reaction injection molding) to extend from the surface of ring core piece.
With respect to the upper surfaces of the end portions on the side of the spoke core pieces, the spoke core pieces are inclined downwards from the ring core piece to the boss. The coating layers covering the upper surfaces of the end portions on the side of the spoke core pieces are thickened with approach to the boss while making their upper surfaces substantially horizontal with a view to obtaining integral appearance with respect to the upper surface of a pad disposed upwardly of the boss.
The thickenings of coating layers on the upper surfaces of connecting parts on the side of the spoke core pieces tend to cause such drawbacks to the coating layers as weld marks or sink marks after the molding process has been effected. For the purpose of preventing the weld or sink marks, as disclosed in Japanese Utility Model Publication Nos. 44056/1983 and 27723/1985, the inserts formed of synthetic resing are set beforehand in the end portions to reduce the thickness of every coating layer itself.
However, the information of coating layers by singly setting the inserts in the end portions before performing the molding process involves a good number of steps and also presents a problem of being costly.